If a computer has 4 gigabytes (GB) of random-access memory (RAM) installed, the system memory that is reported in the System Information dialog box in Windows Vista is less than you expect.
For example, the System Information dialog box may report 3,120 megabytes (MB) of system memory on a computer that has 4 GB of memory installed (4,096 MB).
Note You can access the System Information dialog box in the following ways:
Click Start, type System in the Search box, and then click System under Programs.
Double-click System in Control Panel.
Click Start, right-click Computer, and then click Properties.
Click Show more details in the Windows Vista Welcome Center window.
Note Windows Vista Service Pack 1 (SP1) changed how components of the user interface (UI) report memory. For example, some components of the Windows Vista SP1 UI report when there are 4 GB or more of total physical memory installed on the computer.
For more information about how memory is reported in Windows Vista Service Pack 1, click the following article number to view the article in the Microsoft Knowledge Base:
946003 (
http://support.microsoft.com/kb/946003/)
Windows Vista Service Pack 1 will report 4 GB of system memory (RAM) on systems that have 4 GB of memory installed